MalwareBytes is the best comprehensive virus and spyware blocking program I am aware of. Although there is a free version, the paid version of this product is necessary to fully protect your data if you do get a virus. The free version just checks your machine on demand but the paid version does a great job of stopping bad outgoing data viruses send home. If you do get some spyware, you will notice it actively blocking outgoing data. Before I secured my PC, I was once infected without even knowing it and only found out because MalwareBytes started blocking some outgoing data. I shudder to think what would have happened if my sensitive data was allowed to leave. So if you are unfortunate enough to get a virus that gets through all your protections, it will effectively block outgoing data and you will be so glad you followed this step.